Clamp

ABSTRACT

A clamping apparatus for adjustably clamping a flexible skirt to a conveyor belt skirt plate comprises a locking member adapted to be driven along a stationary cam member in the form of a pin to exert a force on a clamp plate that has one side abutting the flexible skirt and forcing the skirt against the conveyor belt skirt plate. The locking member has a closed, elongated slot to retain the locking member on the cam pin. The locking member may be pivoted outwardly on the pin to project normal to the clamping plate, which has an aligned bore allowing removal of the clamp plate for installation of a flexible skirt. The cam pin is carried on a clamping body that has a narrow waist that is slidably mounted between a pair of opposed retaining flanges on the channel to adjust the position of the clamping plate relative to the conveyor skirt plate.

FIELD OF THE INVENTION

This invention relates to clamps and more specifically to clampingdevices for securing skirts to skirt plates in position along the edgezones of a conveyor belt.

BACKGROUND OF THE INVENTION

It is well-known, particularly with so-called volume conveyor belts inmining, to provide upright wear plates above the usually-upturned sidestrips of the belt. Such plates act as guides or doctors to contain theflow of, for example, coal which is being conveyed. The wear platesterminate a short distance above the belt and, to counter the inevitablemigration of smaller coal particles, it is also known to provide outerskirt plates which are mounted on the wear plates and carry usuallyresilient skirts to more-or-less engage the (moving) conveyor belt nearits outer edges. Particularly in cases where high volume flow is notrequired and/or when the material conveyed is not very abrasive, wearplates may not be necessary and all the necessary containment can beeffected by skirt plates and skirts. One problem associated withconveyor belt skirts which, acting almost as scrapers, require periodicadjustment and/or replacement, lies in the difficulty of removableattachment to the skirt plates. Various clamping systems have beenemployed, but none has been very satisfactory for reasons including highcost, complexity and the inclusion of separable parts such as wedgeswhich, if not tethered, can readily be lost in the often dimly-lit andusually hazardous environment of a mine gallery.

OBJECTS AND SUMMARY OF THE INVENTION

In accordance with the present invention, a flexible skirt may bereleasably and adjustably clamped to a conveyor skirt plate by driving alocking member with a hammer to cause an inclined ramp surface in anelongated slot in the locking member to slide along a stationary pin ofa clamp body. As the locking member slides along the pin in the clampingdirection, it exerts a force on a clamp plate that has an abutmentsurface abutting the skirt and exerting a clamping force to clamp theflexible skirt against the skirt plate. To release the clamping force inorder to adjust the position of the skirt relative to the conveyor belt,the locking member is driven in the opposite direction with the rampsurface sliding along the pin and decreasing the force applied by thelocking member to clamp member and from the clamp member to the flexibleskirt.

Preferably, the position of the clamp member, the clamp body and thelocking member may be shifted longitudinally along skirt plate to exerta clamping force at different locations longitudinally with respect tothe conveyor belt. To this end, a channel is mounted on the skirt plateabove the flexible skirt, the clamp body, and blocking member areslidable along the channel when the locking member is in its releaseposition. Preferably, the clamping member has a bore in its large enoughto permit the locking member to pass therethrough when the clamp memberis pivoted to a position at right angles to the clamping plate. Thus,the clamping member may be removed for installing or when replacing aflexible skirt. The pin retains the locking member on the clamping bodybecause the pin is in the elongated slot which is a closed slot. Thus,the locking member will not be separated from the clamping body andbecome lost.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way ofexample, with reference to the accompanying drawings in which:

FIG. 1 is a half sectional view of a conveyor belt system incorporatingwear plates and also skirt plates and skirts clamped in accordance withthe invention;

FIG. 2 is a fragmentary view on a larger scale, of the system shown inFIG. 1;

FIG. 3 is a side elevation of a clamp;

FIG. 4 is a plan view of one type of clamp plate;

FIG. 5 is a side elevation, partially sectioned of a clamp as used in aright angle relation to a conveyor belt;

FIG. 6 is a side elevation, partially sectioned, of a clamp usedvertically with a conveyor belt;

FIG. 7 and 8 show a clamp in a released and clamped position;

FIG. 9 and 10 show two styles of closed loop cotters; and

FIG. 11 shows an end view of a one piece clamp plate.

BEST MODE AN OTHER EMBODIMENTS OF THE INVENTION

A clamp of the present invention may be used in a variety ofapplications. For example, referring to FIG. 1 of the drawings, aconveyor belt 10 is of conventional trough-section form having upturnedside zones 11 extending outwardly from a generally flat central zone 12.Central rollers 13 support zone 12 of the belt, and outer idler rollers14 support the zones 11. Mounted on a frame extending along the conveyorbelt, are upright wear plates 15 of steel which terminate at their lowerends in welded beads 16 spaced a short distance above the adjacent beltzone 11. A profiled steel skirt plate 17 is bolted (at 18) to each wearplate 15 at intervals along its length, to lie at right angles to theadjacent zone 11 of the belt, and a robust rubber skirt 19 is clamped tothe plate 17 by a series of clamping devices 20 according to the presentinvention.

As more clearly illustrated in FIGS. 2 and 3, a clamping device 20includes a generally cylindrical body member 21 comprising a circularwaisted base 22 and a pair of lugs 23 which extend upwardly from andcontinue the outer cylindrical form of the base. The member 21 isdimensioned so that the base enters one of a series of open-endedchannel-shaped runners 24, of standard section if desired, weldedintermittently along the skirt plate 17 with opposed, inwardly extendingflanges on the channel walls which enter the waist 22A. Each of theclamping devices 20 may be slid within the channel to shiftlongitudinally with respect to the skirt plate 17 and the conveyor belt.The clamping devices may be attached to the skirt plate in othermanners. A pin 25 is secured between the spaced lugs 23, and an elongatelocking member or captive cotter 26 according to the invention isattached by means of the pin 25 which passes through central opening 27in the member 26; the attachment is permanent until such time as the pin25 may be intentionally extracted.

As best shown in FIG. 3, the member 26 defines a closed uninterruptedloop and is formed as an elongate steel plate having a central opening27 shaped to provide, in conjunction with the lower elongate face 28 ofthe member, at least one ramp-like surface 29 for engagement with thepin 25. As shown in FIGS. 9 and 10 each member 126 may have two ramplike surfaces 29, 129. With reference to FIG. 10, locking member 126 hasa ramp-like surface 129 formed with a series of shallow recesses orundulations to minimise the danger of disengagement with the pin 25.

The other component of the device 20 is clamp plate 30 which isillustrated also in FIGS. 4 and 11. In the example of FIG. 4 and FIG. 2,the rectangular plate 30 is formed of steel, with a circularthrough-opening 31 and has welded at one end an abutment bar 32 and atthe other end an abutment 33 in the form of a length of angle iron. Inthe example of FIG. 11, the abutment surfaces are integrally formed andnot welded on.

As shown in FIG. 5, where the clamp 20 is used with a skirt which isperpendicular to a conveyor surface, the base 22 of the body member ofeach of the number of devices 20 required is passed through the openingor bore 31 in its clamp plate 30, and entered into the appropriaterunner 24 and slid along to any required position. Alternatively, thebody member 21 is first fitted in the channel and the clamp plate isthen placed over the body member which can pass freely through theopening 31. The rubber skirt 19 is then correctly positioned against theskirt plate 117 (17) and clamped in position as follows: each lockingmember is shifted from the position A (FIG. 5) which has allowed passagethrough the plate opening 31, to position 8 and then turned through 90°where the bottom face 128 lies against the clamp plate 30, and thelocking plate 26 is hammered or otherwise driven to the position shownin FIG. 3. When driven, the ramp face 129 (29) engages the anchored pin25 to urge the clamp plate and thus its abutments downwardly so that theabutment 32 firmly engages the skirt 19, locking the skirt in positionagainst the plate.

As shown in FIG. 6, the clamp 20 may be used in a vertical orientationwith the skirt 19 contacting the belt at an angle.

The clamping operation is shown in more detail in FIGS. 7 and 8. Notethat the locking member 26 comprises a closed loop having a centralopening 150 which defines two inner ramped surfaces 151, 152. The widthW of the locking member is narrow enough to pass through the bore 31 ofwhatever type or style of clamp plate is used. The central opening 150of the locking member also may include a widened end 153 to facilitaterotating and positioning the member when the pin 25 is located throughthat end. Note that with the clamp plate 130 shown in FIGS. 7 and 8, theabutment 132 is integral and bent about 90° with respect to the portionof the clamp plate against which the locking member 26 bears.

FIGS. 9 and 10 show two styles of locking member 126. Both include adiagonal central opening 150 which defines two ramp surfaces 29, 129 andan enlarged end 151 of the opening 150. One corner 152 is rounded nearthe enlarged end 151. This feature allows the locking member 126 topivot more easily.

FIG. 11 shows a cross-section of a clamping plate 130 formed integrallyfrom a single steel plate. The plate 130 further comprises a flatportion 160 against which an outer surface of a locking pin bears. Theflat portion 160 has a bore 31 through which may pass through both thebody member 21 of the device 20 and the locking member 26. One end ofthe plate 30 is an abutment 161 which is bent about 90° with respect tothe flat portion 160. The other end 163 abuts the skirt and may have avariety of configurations. In the example shown, the skirt clampingabutment 163 is roughly L-shaped in cross-section and is formed at theend of a ramp 164 which extends from the flat portion 160 to the skirtclamping abutment 162.

The clamping devices described above, according to the invention, haveproved extremely satisfactory in use, not only as regards their clampingfunction but also as regards ease of use and absence of accidental lossof parts. Further, the devices are of simple, reliable construction andare relatively inexpensive to produce.

Modifications may be made without departing from the scope of theinvention. For example, the bar (32) or an equivalent abutment may bewelded to the skirt plate rather than to the clamp plate. Also, a broadrib or other abutment may be formed along the skirt and so avoid therequirement for the abutment 33. Such modifications would simplify the(removable) clamping devices. Furthermore, instead of being of circularsection, the body members (21) may be of square or other rectangularsection, to pass through square or like openings (31) in the plates 30.In this case, the locking member (29/129) could not swivel 360° as inthe above examples, but the square-section member (21) would have theadvantage of not requiring the milling of a full recess (22A) and,indeed, a shoulder may suffice for engagement with the flanges of thechannel-shaped runners 24.

INDUSTRIAL APPLICATION

The invention has many industrial applications where metal parts must beremovably clamped together. Two concrete examples are illustrated inFIGS. 5 and 6, for example, with respect to conveyor belt skirtclamping.

We claim:
 1. A clamping apparatus for clamping a flexible skirt to askirt plate along an edge of a conveyor belt, said clamping apparatuscomprising:a clamp body mounted on the skirt plate and projectingoutwardly therefrom, a locking member formed with an elongated slottherein and having a cam surface thereon; a cam means on the clamp bodyhaving a camming engagement with the cam surface on the locking memberand protecting through the elongated slot and allowing the lockingmember to pivot between a release position and a locking position: aclamp member operable by the locking member to move to increase ordecrease the clamping force to hold the flexible skirt against the skirtplate: and a force applying portion on the clamping member for exertingthe clamping force on flexible skirt to clamp the flexible memberagainst the skirt plate; a channel-shaped runner being secured to theskirt plate and slidably receiving the clamp body for sliding movementin the runner to adjust the location of the clamp body and the lockingmember and clamp member carried by the clamp body relative to the skirtplate.
 2. A clamping apparatus in accordance with claim 1 wherein thecam means comprises a pivot pin projecting through the elongated slotand retaining the locking member on the clamp body, the locking membercomprises a plate having the cam surface thereon in the form of aninclined ramp surface on one side of the elongated slot for cammingengagement with the pivot pin to exert the clamping force on the clampmember.
 3. A clamping apparatus for securing flexible skirting materialto a skirt plate along edge zones of a conveyor belt, comprising:a clampbody portion including two spaced-apart lugs; a locking member locatedbetween said lugs and formed with an elongated slot therein, anddefining at least one ramp surface; a pin extending between said lugsand through the elongated slot of said locking member and having cammingengagement with the ramp surface; a clamp plate having a bore to passsaid clamp body and locking member therethrough, the locking memberbeing positioned so as to be axially movable relative to said skirtplate and said clamp plate, and between the lugs of said clamp body, soas to releasably exert pressure on said clamp plate; said clamp body andlocking member being passed through the bore in said clamp plate, so asto locate said clamp plate in juxtaposition with said skirt plate;abutment means provided on an underside of said clamp plate for exertinga clamping force on the clamp plate to releasably and adjustable locatesaid flexible skirting material relative to said skirt plate and saidedge zones of said conveyor belt; and an elongated channel-shaped runnerfixed to the skirt plate and having opposed inwardly extending flangesdefining a longitudinal opening therebetween; said clamp body furthercomprising a waist portion; the inwardly extending flanges being adaptedto engage the waist portion of the clamp body, thus allowing the clampbody to slide in the opening along the runner.
 4. A clamping apparatusas claimed in claim 3, wherein the clamp body portion is cylindrical andhas a waist extending completely around the body.
 5. A clampingapparatus as claimed in claim 3, wherein the locking member is in theform of a closed, uninterrupted loop.
 6. A clamping apparatus as claimedin claim 3, wherein the clamp plate is in the form of an integralconstruction.
 7. A clamping apparatus as claimed in claim 3, wherein oneramp surface of the locking member is formed with a series of shallowrecesses for engaging said pin.
 8. A clamping apparatus as claimed inclaim 3, wherein the elongated slot of the locking member includes anenlarged portion; one external corner of the locking member beingrounded.
 9. A clamping apparatus as claimed in claim 3, wherein theelongated slot in said locking member defines two ramp surfaces.
 10. Ina conveyor having a support plate extending adjacent a conveyor belt,the combination comprising:a movable skirt mounted on the support plateand having an upper edge and a lower edge, which is positioned at theconveyor belt to retain material on the conveyor belt; the skirt beingshiftable downwardly after its lower edge has been worn away; a clampingdevice for releasably clamping a portion of the movable skirt to thesupport plate and movable to a release position to allow downwardmovement of the movable skirt when its lower edge is worn; an elongatedlocking member pivotally mounted on the clamping device for pivotingbetween an upstanding position and a locking position; a clamping memberon the clamping device having an opening for aligning with the elongatedlocking member and for allowing the elongated member to pass through theopening when the locking member is in its upstanding position; a face onthe elongated locking member for lying against the clamping body whenpivoted into its locking position; a driving portion on the elongatedlocking member to be struck and driven to slide the face of the lockingmember along the clamping body; camming surfaces on the clamping deviceand locking member to force the face of the locking member tightlyagainst the clamping member; and a clamping end on the clamping memberfor engaging the movable skirt and for releasably clamping the portionof the movable skirt to the support plate in its adjusted position whenthe driving portion has driven the locking member to its lockingposition.
 11. The combination of claim 10 wherein the skirt is made of aflexible material;the clamping body has an upper end in engagement withthe support plate above the upper edge of the movable skirt; a centralportion with the opening therein to receive the upstanding lockingmember; and a lower portion having the clamping end thereon.
 12. Thecombination of claim 11 wherein the upper end projects inwardly from thecentral portion of the clamping member to engage the support plate abovethe upper edge of the skirt; andthe clamping end on the lower portion ofthe clamping member projects inwardly from the central portion to clampthe skirt.
 13. The combination of claim 11 wherein an elongated supportis fastened to the conveyor, and the clamping device is slidably mountedon the elongated support to be shifted laterally along the support todifferent locations to clamp the movable skirt at different locations.14. The combination of claim 13 wherein:the elongated support is achannel-shaped member with opposed, inwardly-extending flanges; and theclamping device has a waist portion engaging the inwardly-extendingflanges to retain the clamping device on the channel member.